The different types of insects that eat grass include armyworms, cutworms, sod webworms, white grubs, spittlebugs and mole crickets. Some other insects that also eat grass and can infest lawns are billbugs and chinch bugs. However, these insects can infest different types of grasses.
Caterpillars, such as the cutworm and armyworm, can eat all types of turf grasses. When these insects are in their larval stages, they can mainly affect the leaves and stems of grass. The damage caused by these pest are patches that start as small irregular patches and spread out feet in width. Although chinch bugs can also affect a wide variety of grasses that include Bermuda and centipede grasses, it causes the most damage to St. Augustine grass.
White grubs, billbugs and mole crickets are found in the soil and eat the roots of the grass. White grubs are the larvae of beetles, and billbugs are weevils. Spittlebugs mainly affect centipede grass.